The present invention relates to the preparation of quaternary ammonium blends and more particularly to the stabilization of such blends.
Quaternary ammonium compounds have found wide acceptance in the marketplace for formulating fabric softeners and anti-stats, floculating agents, emulsifiers (e.g. for asphalt), personal care additives, clay/amine complexes, and the like. Some quaternary ammonium compounds can be unstable under extended storage conditions resulting in phase separation of the product. This same stability problem also can be encountered when dealing with some of the tertiary amine precursor of the quaternary ammonium compound. For some purposes, it is desirable to have the ability to transport and store the amine/quaternary ammonium blend for use as is or converting the amine portion of the blend into a quaternary ammonium compound, especially when end use of the blend is at a manufacturing location quite distant from the manufacturing source of the blend. An example of such instance would involve the manufacture of the amine precursor in one country for shipment to another country located a great distance therefrom. Under such circumstances, the end use country may desire the precursor amine to provide it the flexibility in converting the tertiary amine to different quaternary ammonium compounds, to use the amine precursor as is, or to blend it with other ingredients. Having the ability only to ship the quaternary ammonium product lessens the flexibility were the amine precursor to be able to be shipped and stored.
A practical problem in the extended storage and transport of such materials involves the conditions to which such materials will be subjected. For example, the product may be shipped in a ship cargo hold which may subject the product to high temperatures of storage, especially if the ship were sailing in equatorial waters. In order to provide requisite storage stability to such amine precursor or quaternary ammonium compounds during extended storage and shipment at elevated temperatures, a stabilizing agent or stabilizer often is added. Unfortunately, stabilizers which are suitable for either the precursor amine or for the quaternary ammonium compound often are undesirable for stabilizing blends of a quaternary ammonium compound and amine precursor.